This is a Phase II Small Business Innovation Research (SBIR) grant application to support the further development of an innovative, online training program to aid in the dissemination of Behavioral Activation (BA), a therapy for depression. The current application represents a continued cooperative partnership between the small business, Behavioral Tech Research, Inc., a company dedicated to disseminating effective psychosocial treatments and Dr. Sona Dimidjian, who with colleagues, developed and evaluated the efficacy of BA. BA is an evidence-based treatment for Major Depressive Disorder, which may have particular transportability advantages compared to other psychosocial treatments with the similar aims. The proposed online training program will substantially aid in the vital training and utilization of this evidence-based practice for both community clinicians and clinical students. The course will be based on our successful Phase I program which was rated highly for usability and content. We plan to substantially expand the content of the training to include all remaining content from the primary BA treatment manual. We will expand the program's interactivities to include highly interactive performance-based learning activities that immerse the user within the treatment context. Ultimately, the aims of this Phase II proposal are to;1) Determine content for the final program utilizing an advisory board of BA experts;2) Create the program using an iterative process of development and evaluation;and, 3) Conduct a between-subjects randomized, controlled hybrid efficacy/effectiveness trial (N=240) using an additive research design to evaluate gains in knowledge and application of BA and gains in self-efficacy for conducting BA therapy with patients suffering from major depression. PUBLIC HEALTH RELEVANCE: Major depression is a pervasive and debilitating disorder, for which the majority of individuals receive no or inadequate treatment, despite the fact that efficacious treatments exist. Increasing the availability of such treatments requires widely available and effective training materials that will facilitate the utilization of such approaches by practicing clinicians. Behavioral Activation (BA) is an evidence-based practice for depression that may have important transportability advantages;this project aims to further develop an innovative, interactive online training program teaching the principles of BA, in order to increase the dissemination of this evidence-based treatment and improve clinical outcomes for adults suffering from depression.